/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   This program is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 *

 *   This program is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.sonews.daemon.command;

import java.io.IOException;

import java.util.Set;

import org.sonews.daemon.CommandSelector;

import org.sonews.daemon.NNTPConnection;

import org.sonews.util.io.Resource;

/**

 * This command provides a short summary of the commands that are

 * understood by this implementation of the server. The help text will

 * be presented as a multi-line data block following the 100 response

 * code (taken from RFC).

 * @author Christian Lins

 * @since sonews/0.5.0

 */

public class HelpCommand implements Command

{

  @Override

  public boolean hasFinished()

  {

    return true;

  }

  @Override

  public String impliedCapability()

  {

    return null;

  }

  @Override

  public boolean isStateful()

  {

    return true;

  }

  @Override

  public String[] getSupportedCommandStrings()

  {

    return new String[]{"HELP"};

  }

  @Override

  public void processLine(NNTPConnection conn, final String line, byte[] raw)

    throws IOException

  {

    final String[] command = line.split(" ");

    conn.println("100 help text follows");

    if(line.length() <= 1)

    {

      final String[] help = Resource

        .getAsString("helpers/helptext", true).split("\n");

      for(String hstr : help)

      {

        conn.println(hstr);

      }

      Set<String> commandNames = CommandSelector.getCommandNames();

      for(String cmdName : commandNames)

      {

        conn.println(cmdName);

      }

    }

    else

    {

      Command cmd = CommandSelector.getInstance().get(command[1]);

      if(cmd instanceof HelpfulCommand)

      {

        conn.println(((HelpfulCommand)cmd).getHelpString());

      }

      else

      {

        conn.println("No further help information available.");

      }

    }

    conn.println(".");

  }

}